The current flow path in electromagnetically operated contactors of standard design is frequently in a "C" path. For example, current enters along a first conductor, passes through a set of movable contacts, and exits through a second conductor which is substantially parallel to the first conductor. For example, the first conductor forms the upper arm of the "C", the contacts form the back of the "C", and the second conductor forms the lower arm of the "C". A disadvantage of a "C" shaped current path through a set of contacts is that magnetic forces generated by heavy current flows during short circuit conditions act upon the movable contact in such a way as to force the contacts open. It is disadvantageous to have the contacts of a contactor blow open during short circuit conditions unless the operating coil of the contactor is de-energized with the intent to interrupt the heavy currents experienced during short circuit conditions. Also, an overload protection device in electrical series with the contactor rather than the contactor shold interrupt the current flow when such currrent exceeds the interruption capability of the contactor. For example, a fuse in the circuit should blow rather than the contact of the contactors being forced open by magnetic fields. A fuse is designed to interrupt the heavy current flows experienced during short circuit conditions.
A long-standing problem in the art of the design of electromagnetic contactors has been to design a current flow path in which the electromagnetic forces which tend to blow the contacts apart are minimized by the geometry of the current flow.